The McCain campaign says that the candidate meant to say that the world's largest COAL reserves are in the U.S.

And that's true -- the Energy Information Administration says that the U.S. "has the world's largest known coal reserves, about 263.8 billion short tons. This is enough coal to last approximately 225 years at today's level of use. "

What's odd about this, though, is that McCain has made energy independence the domestic centerpiece of his campaign ("Drill, baby, drill!") not to mention a major reason for picking Alaska Gov. Sarah Palin as his running mate. (McCain said Palin “knows more about energy than probably anyone else in the United States of America.”)

And yet, even with these credentials, the McCain-Palin team has been criticized for getting some basic facts about energy wrong.

Palin told ABC News' Charlie Gibson that "a credential that I do bring to this table" deal "with the energy independence that I've been working on for these years as the governor of this state that produces nearly 20 percent of the U.S. domestic supply of energy…"

McCain in a separate interview told Gibson that Palin has "been governor of our largest state, in charge of 20 percent of America's energy supply."

As Factcheck.org has pointed out, Alaska produces closer to 3.5 percent of the U.S. domestic energy supply.

What about oil? Maybe they meant the U.S. domestic supply of oil?

Actually, Alaskan production accounts for less than 5 percent of the crude oil and petroleum products supplied to the U.S. in 2007 -- including imports from other nations.

The only way this makes sense is if McCain and Palin meant to say that Alaska produces 14 percent (instead of 20) of the oil (not energy) produced entirely in the U.S. (not the entire supply), and that excludes all oil imports and any other form of power.

People make mistakes, but when the McCain-Palin team makes gaffes about their No. 1 domestic issue, they risk stepping on their message.